Expired Canadian patentCanada
Methods for designing contact lenses
CA 2470091 C · Owner: Collins, Michael J. · Inventors: Collins, Michael J.; Davis, Brett A.; Iskander, Daoud R.
Overview
Drawings and full text
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
The invention provides a method for designing lenses and lenses produced thereby in which method locally fitted Chebyshev polynomials are used to design one or more of the lens' surfaces.
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed December 4, 2002 and granted October 22, 2013. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended December 4, 2022.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by December 4, 2024.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
FiledDecember 4, 2002
GrantedOctober 22, 2013
Term endedDecember 4, 2022
Patent numberCA 2470091 C
Classification (IPC)G02C7/04 +1 more
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.